PREPARATION METHOD FOR MEDICAL POROUS METAL MATERIAL FOR WEIGHT-BEARING BONE TISSUE REPLACEMENT

摘要

A preparation method for a medical porous metal material for weight-bearing bone tissue replacement comprising: mixing tantalum powder, a pore-forming agent, and a forming agent, press-forming the powder mixture into an organic foamed body, then degreasing, sintering, cooling, and performing a heating process. The pressure during the press-forming is 50 to 100 Mpa. The degreasing process comprises: gradually increasing the temperature to 400 to 800°C at a speed of 0.3 to 2°C/min, introducing argon gas to form a protective atmosphere, and maintaining the temperature for 300 to 360 minutes. The pore-forming agent is ammonium bicarbonate or hydrogen peroxide. The forming agent is one or multiple of stearic acid, zinc sterate, paraffin, and synthetic resin. Within a vacuum degree of 10^-4 to 10^-3 Pa, increasing the temperature to 800 to 900°C at a speed of 10 to 20°C/min, maintaining the temperature for 240 to 480 minutes, cooling to 400°C at a speed of 2 to 5°C/min, maintaining the temperature for 120 to 300 minutes, and cooling together with the furnace to room temperature. Measurements show that the impurity concentration thereof is lower than 0.2%. The density reaches 6.67 to 8.34 g/cm³, the porosity reaches 50% to 60%, and the pore diameter reaches 150 to 450 μm. The elastic modulus reaches 4.5 to 6.0 Gpa, and the bending strength reaches 100 to 120 Mpa.